An electronic device equipped with a touch device may execute various types of functions based on a touch input. The electronic device executes a scroll function when a single touch input is sensed on a displayed screen, and determines two or more touch inputs as a gesture input, in all cases. According to the conventional art, while a user interacts with an electronic document such as an image or a browser on a touch screen, a scroll function may be executed according to a single touch input, and another operation such as zooming-in/out may be executed according to a multi-touch input involving two or more inputs.
When a plurality of touch inputs are generated, the electronic device unnecessarily and continuously tracks movement of a finger so as to calculate, for example, a scale factor in a zoom operation, and/or execute a scroll or gesture operation in real time based on the calculation. For example, when the number of touch inputs that a portable touch device may simultaneously detect is ten, a user may have difficulty placing ten fingers on the single screen. However, even in this circumstance, the user may easily make a motion of scrolling in one direction. The user motion pattern may thus be more limited when the size of a screen is small. In particular, in a case of a smart phone and a tablet, a limited battery capacity limits the time the terminal maybe utilized. Power may be wasted because of tracking of unneeded or unutilized touch inputs and attendant calculations, which may even cause a problem or input errors. For example, several touch inputs may be unintentionally input causing a scroll and gesture operation, which may constitute an input error or even a malfunction.